The primary focus of the classical forms of Okinawan karate; Sanchin
and Naihanchi is on the development of efficient or correct posture.

Both forms work on the leg and pelvic floor muscles necessary for good
posture. Naihanchi especially works on strengthening the leg muscles
and Sanchin the pelvic floor muscles. Chojun Miyagi Sensei, founder
of Goju Ryu considered that these were two of the three most important
fundamental kata, the third being Tensho that frees the upper chest
and back.

Work on correcting a lifetime of bad posture starts from the ground
up and requires strong leg, pelvic and abdominal muscles.

Begin by standing up tall in the stance. Feeling the spine grow long,
taking the kinks out of the body.

Then allow the body to sink, relaxing but maintaining core firmness.
The chest and chin should sink and the shoulders drop as you release
the excess tension. As you let go, the centre of gravity lowers and
the weight distribution is focussed in the feet at the inside the ball
of the foot and below the base of the big toe.

This point is known as the 'bubbling well', or Kidney 1. In Traditional
Chinese Medicine (TCM) from this point issues the ground energy and
directs it to the Kidneys where it enters the blood stream and becomes
body chi/Ki (energy).

If dropping a plumb line from the outside of each knee it should come
to rest above the base of the big toe/bubbling well point. This way
the weight of the body is largely taken by the skeleton.

It is imperative that the lumbar spine and neck are held straight in
a lithe natural way, both balanced and support by the skeleton rather
than muscular effort.

It is common to see a very wide low Shiko Dachi, back curved with backside
stuck out and the chest stuck out. Whilst it may look correct is does
not necessarily follow any martial concepts and may have little value.

With the backside stuck out, there is very little balance or rooting
and with the chest expanded, the solar plexus is very vulnerable.

When undertaking standing practise in Shiko Dachi, sink keeping the
lower back straight, pulling the tail bone under. When you feel the
tension in the upper thigh, rotate the pelvis up so that you feel a
similar tension a the top of the hamstring (base of the buttocks). Balance
this with another feeling of tension in the lower abdomen, this creates
a triangulation of forces maintaining correct posture.

This will strengthen the leg, lower back and abdominal muscles.

In Sanchin the same principles apply but in a more narrow stance. This
focuses more on the pelvic muscles strengthening muscles around the
perineum. An additional contraction on the anal sphincters pulls everything
together. This is a feeling of pulling up not pushing down though.

Standing practise will build a strong foundation through natural and
correct posture. From this comes the martial power and health benefits.

The power comes from the ground through the legs and hips, when this
is attained then the channelling of this energy through the waist, trunk
and arms can be developed.